Table 3.

Structural components of the GNPs for brain tumor diagnosis.

Structural features of GNPs		Examples (number of studiesa)
GNP shape		Gold nanosphere (GNS) (12) Gold nanostar (GNSt) (2) Gold nanorod (GNR) (2) Gold nanocage (GNC)
GNP size		20–120 nm
GNP coating		Polyethylene glycol (PEG) (8) Silica shell (2) PEG and silica shell
GNP imaging tags	Raman tag	Trans-1,2-bis(4-pyridyl)-ethylene (3) IR783B N,N-dimethylformamide
	Fluorescent tag	Phthalocyanine 4 (Pc4) (2) Mercapto-urodecanoic acid (MUA) Cytochrome 647 (Cyto 647)
	MRI tag	Gadolinium (4)
BBB-crossing enhancers	Internal (on-surface)	RGDyK (2) transferrin (Tf) (2) Fibroblast growth factor (FGF) Low-density lipoprotein-receptor-related protein-1 (LRP-1) Transactivator of transcription (TAT) Anti-epidermal growth factor receptor antibody (anti-EGFR AB) Folate, EpCam, CD 45
	External	MR-guided focused ultrasound (MRgFUS) ultra-short pulsed laser

^aNumber is reported only if >1.

GNP, gold nanoparticle.